4-(ricinoleoyl) derivatives of morpholine



United States Patent 2): America as represented by the Secretary ofAgricul- No Drawing. Application Nov. 18, 1959, Ser. No. 859,-

831, now Patent No. 3,652,630, dated Sept. 4, 1962, which is a divisionof application Ser. No. 786,661, Jan. 13, 1959. Divided and thisapplication Feb. 2, 1962, Ser. No. 179,828

4 Claims. (Cl. 260-2417) (Granted under Title 35, U.S. Code (1952), sec.266) A nonexclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant subiicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This application is a division of Serial No. 859,831, filed November 18,1959, now Patent No. 3,052,680, which in turn was a division of SerialNo. 786,661, filed January 13, 1959, now Patent No. 2,971,855.

This invention relates to nitrogencontaining derivatives of ricinoleicacid. More particularly, this invention relatcs to the morpholides andcyanothylated derivatives of ricinoleic acid and its derivatives. Thesenitrogen-containing compounds have utility as plasticizers for bothvinyl chloride polymers and for cellulose esters.

Ricinoleic acid is a unique fatty acid found in castor oil in the formof an ester of glycerol. Ricinoleic acid normally comprises about 90% ofthe fatty acids present, as glycerides, in castor oil. Chemically,ricinoleic acid is IZ-hydroxyoleic acid or 12 hydroxy 9 octadecenoicacid which may be represented by the following formula:

A morpholide of an acid is an amide of the acid in which the amidonitrogen atom is a nitrogen atom of a morpholine ring. Prior workershave produced the morpholides and other amides of some of the morecommon fatty acids. The morpholides have generally been prepared by thereaction of morpholine with acid chlorides, acids, or acid anhydrides.

Cyanoethylated derivatives are conventionally produced by vinyl additionof acrylonitrile (CH =CHCN) to reactive hydrogen atoms contained inalcohols, phenols, and the like compounds. Each reactive hydrogen atomcauses a vinyl group of the acrylonitrile to become saturated, thusproducing cyanoethylated derivatives having beta-substitutedpropionitrile groups attached via ether linkages. The cyanoethylationreaction has been applied in the prior art to a lar e number ofmonohydric and poly. hydric alcohols, as well as to numerous othercompounds having reactive hydrogen atoms.

A primary object of the present invention is to provide processes forproducing new morpholides and cyanoethylated derivatives of ricinoleicacid and its derivatives. A further object is to produce novelnitrogen-containing plasticizers from ricinoleic acid and itsderivatives, said plasticizers being suitable for plasticizing eithervinyl chloride polymers or cellulose esters. Other objects will beapparent from the description of the invention.

In general, according to this invention, the esters of ricinoleic acidand of its derivatives are reacted with morpholine to produce themorpholides. It is generally preferred to use the methyl esters for thisammonolysic reaction, although other esters such as ethyl esters, propylesters etc. may also be employed. When the preferred methyl esters aresubjected to the ammonolysis reaction CROSS REFERENCE EXAMllikliPatented Feb. 25, 1953 with morpholine, the hydrogen atom of thesecondary amine structure of the morpohline combines with the methoxylgroup of the ester to yield methyl alcohol and the morpholide, accordingto the following equation:

CH:CH2 0 N-H omo-o-P.

\OHPCHI ODE-CH2 O CHaOH 0 N CHz-CH:

where R represents an alkyl or alkenyl group having an alcoholichydroxyl substituent. The hydroxyl group can either be left free andunreacted, or it can be made to react with any of the reactants commonlyused for reacting with alcoholic hydroxyl groups.

Suitable methyl ester reactants include: methyl ricinoleate; methyll2-hydroxysteerate; methyl ricinolaidate; and the like. Suitablereactants for introducing substituents on the hydroxyl groups of themorpholides include acetic anhydride for making acetoxy derivatives,acrylonitrile for making cyanoethylated derivatives, and the likereagents commonly used for reacting with alcoholic hydroxyl groups.

The reaction for preparation of morpholides according to this inventionproceeds smoothly at relatively moderate temperatures in the absence ofa catalyst. The morpholides can be obtained in substantiallyquantitative yield simply by refluxing the methyl esters withmorpholine, while at the same time distilling off the methyl alcohol asit is formed in the reaction. This is the preferred procedure. Since thedistillation temperature of methyl alcohol is quite low as compared tothat of morpholine, eiiicient fractionation is not required andrelatively little of the morpholinc distills over with the methanolduring the course of the reaction. The progress of the reaction can befollowed conveniently by observing the rise in reflux temperature ormore accurately by titrating aliquots of the reaction mixture toascertain the quantity of unreacted morpholine remaining.

It is generally preferred to carry out the reaction at a temperature atleast as high as the reflux tern erature oi the particular mixture ofreactants being employed. Temperatures considerably lower than this arenot generally suitable, since the rate of reaction becomes too slow tobe practical. Extremely high temperatures are not desirable, especiallywhen unsaturated methyl ester reactants are used, since there is dangerof degradation, modification, or decomposition of the reactants.

While the morpholine and the ester reactants combine in a 1:1 ratio, itis usually preferred to employ an excess of morpholine. About 2 moles ofmorpholine for each mole of ester is particularly suitable.

The length of reaction time can be' controlled depending on the paicular reactants being employed and the extent of conversion desired bythe operator. Essentially complete conversion to the morpholide isusually achieved in about 36 hours under the preferred conditions.

Although suitable unreactive solvents for the reactants can be used inthe reaction mixture, it is not generally desirable or advantageous toemploy such solvents. The morpholine and ester reactants are mutuallysoluble and provide a homogeneous reaction mixture without theincorporation of a solvent.

The isolation and recovery of the morpholide product can be accomplishedwithout difiiculty. At the end of the reaction period, the excessmorpholine is removed, preferably by distillation at a pressure belownormal atmospheric pressure. The morpholide product remaining can beused without further purification, or it can be purified by conventionalmeans. Distillation, solvent crystallization, and the like are generallypreferred means for purifying the morpholides.

The unreacted hydroxyl group of the morpholide products of the presentinvention can be acylated with the usual acylating agents under theconditions conventionally employed for acylation. For example, uniqueacetoxy derivatives can be prepared by treating said morpholides withacetic anhydride. It is generally preferred to use an excess of aceticanhydride and heat the reaction mixture to a temperature below thedecomposition temperature of the reactants during the acylation. It isconvenient to employ about 1 part by weight of the acetic anhydride foreach part by weight of morpholide, and to carry out the acylationreaction at the reflux temperature of the reaction mixture until thedesired extent of reaction is obtained. The acetoxy derivative isreadily isolated by means of distillation or other conventionalprocedures.

In preparing cyanoethylated derivatives of ricinoleic acid derivativesaccording to the process of the present invention, acrylonitrile isreacted with the reactive hydrogen atoms of the alcoholic hydroxylgroups of the ricinoleic acid derivatives. The cyanoethylated productscontain beta-substituted propionitrile groups attached by means of etherlinkages. For example, when 4-ricinoleoylmorpholine is the reactantbeing cyanoethylated the reaction can be represented by the followingequation:

Suitable reactants which can be cyanoethylated include: 4ricinoleoylmorpholine; 4 (12 hydroxystearoyl)- morpholine; ricinoleylalcohol; and the like. When ricinoleyl alcohol is used as the reactant,both of the alcoholic hydroxyl groups of said reactant arecyanoethylated to yield the di-cyanoethoxy compound, namely 1,12-di-beta-cyanoethoxy-9-octadocene.

The cyanoethylation reaction proceeds readily at moderate temperaturesin the presence of an alkaline catalyst. Any of the conventionalalkaline catalysts, such as metallic sodium or potassium (producing thecorresponding alkoxides) may be used. We prefer to employ a quaternaryam ne base type catalyst, such as benzyltrimethylammonium hydroxide andthe like. The concentration of catalyst in the reaction mixture can bevaried widely. About 0.04 part by weight of quaternary amine for 1 partby weight of reactant being cyanoethylated is particularly suitable.

It is generally preferred to conduct the reaction in a suitable solventmedium. Any solvent in which the reactants are soluble and which isunreactive toward the reactants is generally suitable. Dioxane is aparticularly suitable solvent. The quantity of solvent employed can bevaried widely, but about 1 part by weight of solvent for each part byweight of reactant being cyanoethylated is usually preferred.

The relative amounts of ricinoleic acid derivative and acrylonitrile inthe reaction mixture can be varied widely. However, since these tworeactants combine in a 1:1 ratio for each hydroxyl group undergoingcyanoethylation, it is desirable to assure at least this theoreticalratio in the reaction mixture. An excess of acrylonitrile is usuallypreferred. About 2 moles of acrylonitrile for each mole of hydroxylgroup in the reactant being cyanoethylated is particularly suitable.

The use of a polymerization inhibitor in the reaction mixture isdesirable. Otherwise, an excessive amount of the acrylonitrile willpolymerize to form polyacrylonitrile and thus be unavailable for thecyanoethylation reaction. Water is preferred, in view of the fact thatit is an economical and effective polymerization inhibitor. When usingwater, we prefer to use about 0.1 part by weight of inhibitor for eachpart by weight of reactant being cyanoethylated.

While temperatures ranging from about room temperature to thedecomposition temperature of the reactants can be used, maximumtemperatures of from about 70 C. to about 85 C. are particularlysuitable for employment in the cyanoethylation process of the presentinvention. A preferred procedure is to add the acrylonitrile to thereaction mixture at such a rate that as the reaction proceeds thetemperature of the mixture gradually rises to the preferred maximumreaction temperature (about 70 C. to 85 C.). Following complete additionof the acrylonitrile, the reaction mixture is maintained at the saidpreferred maximum reaction temperature a suf ficient length of timeuntil the desired extent of cyano-- ethylation is achieved. From about50% to about 80% conversion to cyanoethylated product is achieved inabout 3 to 4 hours under the preferred reaction conditions. Thecyanoethylated product can be isolated and recovered without diflicultyby employing conventional procedures such as phasic separations,distillations, crystallization from solvents and the like.

The nitrogen-containing derivatives of the present invention have uniqueplasticizing properties. They exhibit good compatibility with polymersand copolymers of monomers predominating in vinyl chloride, such aspolyvinyl chloride, and the vinyl chloride-vinyl acetate copolymerspredominating in vinyl chloride. They can be employed as plasticizers inproportions of from about 10 to parts by weight per parts by weight ofpolymer. In addition, some of the nitrogen-containing derivatives arelikewise suitable as plasticizers for cellulose esters, such ascellulose acetate. They can usually be employed in proportions of up toabout 40 parts by weight per 100 parts by weight of cellulose acetateand still exhibit good compatibility. The suitability of the nitrogencontaining derivatives of this invention as plasticizers for two suchwidely difierent types of materials is unique.-

The following examples are given by way of illustration and not by wayof limitation of the invention.

EXAMPLE 1 A mixture of 312 grams (1 mole) of methyl ricinoleate and 174grams (2 moles) of morpholine was heated in a reaction flask undergentle reflux for about 36 hours. The methyl alcohol produced during thecourse of the reaction was allowed to distill out of the reaction flaskthrough a short Vigreux column and condensed in a Dean-Stark trap.During the 36 hour reaction period, the reaction temperature graduallyrose from to C. and approximately 1 mole of methyl alcohol was evolved.At the end of the reaction period, the unreacted morpholine was removedby distillation under vacuum. The reaction product was distilled,yielding 320 grams of material distilling at 243246 C. at 0.2millimeters: N 1.4891; 11 0.9756; [111 4.38. The purified prodnotcontained 71.47% carbon, 11.02% hydrogen, 3.80% nitrogen, and 4.68%hydroxyl, as determined by conventional analytical procedures. Theproduct was thus shown to be 4-ricinoleoylmorpholine which has atheoretical content of 71.88% carbon, 11.24% hydrogen, 3.81% nitrogenand 4.63% hydroxyl.

The 4-ricinoleoylmorpholine was compared with di(2- ethylhexyDphthalate,DOP, as the plasticizer in a standard formulation comprising: 63.5% of avinyl chloridevinyl acetate (95-5) copolymer, 35% plasticizer, 0.5%stearic acid, and 1.0% basic lead carbonate. The results are given inTable I. e

The compatibility of the plasticizers with the vinyl chloride polymersin all of the examples was determined on the basis that exudation orbleeding out of the plasticizer within days was poor, and a lack ofbleeding for at least 45 days was good."

The 4-ricinoleoylmorpholine was also tested as a plasticizer forcellulose acetate. Thirty parts by weight of plasticizer and 100 partsby weight of cellulose acetate (40% acetyl content) were dissolved inacetone, and cast films were prepared from the acetone solution byallowing the solvent to evaporate slowly from portions of the solutionplaced in shallow dishes. The films were stripped from the dishes,heated 1 hour at 80 C., and examined. The films were dry and clear,indicating compatibility of the plasticizer with the cellulose acetate.

EXAMPLE 2 characteristics: N 1.4789; 1 0.9836; [(11 20.35. 3

It was found to contain 69.99% carbon, 10.53% hydrogen, 3.24% nitrogenand 0% hydroxyl. The product was thus shown to be4(12-acetoxyoleoy1)morpholine which has a theoretical content of 70.37%carbon, 10.58% hydrogen, 3.42% nitrogen, and 0% hydroxyl.

The 4-(12-acetoxyoleoyl)morpholine was compared with DOP in the standardformulation described in Example 1. The results are given in Table II.

Table II Cor pati- Tensile 100% Elonga- Brittle bility strength,modulus, tion, p i t,

p.s.i. p.s.i. percent C.

4-(12-acetoxyoleoyl)morpholine 01000.... 2,990 1,370 340 -23 OP d0 3.0001, 050 320 31 The 4-(12-acetoxyoleoyl)morpholine was tested as aplasticizer for cellulose acetate acetyl) as described in Example 1.Good compatibility was obtained using either thirty or forty parts byweight of plasticizer per 100 parts by weight of cellulose acetate.

EXAMPLE 3 A mixture of 314 grams (1 mole) of methyl 12-hydroxystearateand 174 grams (2 moles) of morpholine was reacted in the same manner andunder the same conditions as described in Example 1. After removal ofunreacted morpholine by vacuum distillation, the reaction product wasdistilled, yielding 330 grams of material distilling at 245249 C. at0.25 millimeter. The purified product obtained by crystallization ofthis distillate from commercial hexane contained 71.53% carbon, 11.79%hydrogen, 3.75% nitrogen, and 4.59% hydroxyl. The product was thus shownto be 4-(IZ-hydroxystearoyl)morpholine which has a theoretical contentof 71.49% carbon, 11.73% hydrogen, 3.79% nitrogen, and 4.60% hydroxyl.

EXAMPLE 4 One part by weight of the 4-(12-hydroxystearoy1)- morpholineof Example 3 was refluxed with 1 part by weight of acetic anhydride forabout 2 hours. The acetic acid and excess acetic anhydride were thenremoved by vacuum distillation. The reaction product was purified bydistillation at 0.2 millimeter pressure, its distillation temperaturebeing 234235 C. at this pressure. The purified product had the followingcharacteristics: N 1.4709; d 0.9726. It was found to contain 69.62%carbon, 11.17% hydrogen, 3.24% nitrogen, and 0% bydroxyl. The productwas thus shown to be 4-( l2-acetoxystearoyl)morpholine which has atheoretical content of 70.03% carbon, 11.02% hydrogen, 3.40% nitrogen,and 0% hydroxyl.

The 4-(12-acetoxystearoyl)morpholine was compared with DOP in thestandard formulation described in Example 1. The results are given inTable III.

Table III Conp'iti- Tensile 100% Elonga- Brittle bility stren th,modulus, tini, poi t,

p.s.i. psi. percent C.

4-(12-qcetoxystearoyl) norpholine Good 2.980 1.510 300 21 DOP o 3,0001,650 320 31 EXAMPLE 5 EXAMPLE 6 368 grams (1 mole) of the4-ricinoleoylmorpholine of Example 1 was dissolved in 368 grams ofdioxane. To this solution was added 37 milliliters of water as apolymerization inhibitor and 37 milliliters of Triton B (a 40% by weightsolution of benzyltrimethylammoniurn hydroxide in methyl alcohol) ascatalyst. Two moles (106 grams) of acrylonitrile was then added dropwiseto a the mixture with stirring during a 30-minute period, during whichtime the temperature rose to about C. The reaction mixture was stirredand maintained at about 75 C. for three additional hours, and was pouredwhile still warm into 3 liters of diethyl ether. The solution wasallowed to stand a few hours to precipitate most of thepolyacrylonitrile. The ethereal solution was decanted from theprecipitate, filtered, and the filtrate was neutralized with diluteaqueous hydrochloric acid and then washed free of excess acid withwater. The resulting ethereal layer was vacuum distilled to removeether, and then distilled rapidly under high vacuum to isolate thecyanoethylated product. The fraction which distilled at 248254 C. at 20microns pressure was purified by crystallization from 15 volumes ofmethyl alcohol at -70 C. overnight. The purified product had thefollowing characteristics: N 1.4816;

It was found to contain 70.74% carbon, 10.40% hydrogen, and 6.64%nitrogen. The product was thus shown to be4-(1Z-beta-cyanoethoxyoleoyl)morpholine which has a theoretical contentof 71.38% carbon, 10.54% hydrogen, and 6.66% nitrogen.

The 4-(12-beta-cyanoethoxyoleoyl)morpholine was compared with DOP in thestandard formulation described in Example 1. The results are given inTable IV.

' hydrogen, and 6.55% nitrogen.

Table IV Corrpati- Tensile 100% Elonga- Brittle bility strength modulus,tion, pcint,

p.s.i. p.s.i. percent C.

4-(12-beta-cyanoethoxyoleoyD- morpholino Good 3,000 1.550 340 '15 DOP do3,000 1,560 350 33 EXAMPLE 7 370 grams (1 mole) of the4-(12-hydroxystearoyl)- morpholine of Example 3 was cyanoethylated with106 grams (2 moles) of acrylonitrile in the same manner and under thesame conditions as described in Example '6. In this case, theacrylonitrile was added during a 20- minute period and the temperatureof the reaction mixture rose to about 80 C. The mixture was then stirredand maintained at 70 C. for three additional hours. The reaction mixturewas further processed as described in Example 6. The fraction of thereaction product which distilled at 246252 C. at 25 microns pressure waspurified by crystallization from volumes of acetone at 25 C. overnightto precipitate non-cyanoethylated morpholide. Acetone was removed fromthe resulting filtrate -by vacuum distillation to obtain thecyanoethylated morpholide. It was recrystallized from volumes of methylalcohol at 70 C. overnight. The recrystallized product contained 70.85%carbon, 10.85% The product was thus shown to be4-(12-beta-cyanoethoxystearoyl)morpholine which has a theoreticalcontent of 71.04% carbon, 10.97% hydrogen, and 6.63% nitrogen.

The 4-(1Z-beta-cyanoethoxystearoyl)morpholine was compared with DOP inthe standard formulation described in Example 1. The compatibility ofthe 4-(12- beta-cyanoethoxystearoyl)morpholine was good. Its percentelongation Was 380% as compared to 320% for DOP, and its tensilestrength was 3120 psi. as compared to 3000 psi. for DOP.

EXAMPLE 8 1284 grams (1 mole) of ricinoleyl alcohol was dissolved in 284grams of dioxane. To this solution was added 28 milliliters of water asa polymerization inhibitor and 28 milliliters of Triton B (a 40% byWeight solution of benzyltrimethylammoniurn hydroxide in methyl alcohol)as catalyst. Four moles (212 grams) of acrylonitrile was then addeddropwise to the mixture with stirring during a 1-hour period, duringwhich time the temperature rose to about C. The reaction mixture wasstirred and maintained at about 70 C. for three additional hours, andwas poured while still warm into 3 liters of diethyl ether. The solutionwas allowed to stand a few hours to precipitate most of thepolyacrylonitrile. The ethereal solution was decanted from theprecipitate and the ether was removed from the solution by vacuumdistillation. The residue was distilled rapidly under high vacuum. Thefraction which distilled at 228 -238 C. at microns pressure wascrystallized from 15 volumes of methanol at 70 C. overnight. Thepurified product had the following characteristics: N 1.4632;

a fg 14.30

It was found to contain 74.20% carbon, 11.18% hydrogen, and 7.08%nitrogen. The product was thus shown to be1,12-di-beta-cyanoethoXy-9-octadecene which has a theoretical content of73.79% carbon, 10.84% hydrogen, and 7.17% nitrogen.

The 1,12-di-beta-cyanoethoXy-9-octadecene wascompared with DC? in thestandard formulation described in Example 1. The results are given inTable V.

1. 4-ricinoleoylmorpholine.

2. 4-(12-hydroxystearoyl)morpholine.

3. 4-ricinolaidoylmorpholine.

4. A compound of the group consisting of '4-ricinoleoylmorpholine,4-(12-hydroxystearoyl)morpholine, and 4-ricinolaidoylmorpholine.

References Cited in the file of this patent UNITED STATES PATENTS Litvanet al. Aug. 9, 1960 OTHER REFERENCES Dupuy et al.: J. American OilChemists Society, vol. 35, pages 99-102 (1958).

4. A COMPOUND OF THE GROUP CONSISTING OF 4-RICINOLEOYLMORPHOLINE,4-(12-HYDROXYSTEAROYL)MOROPHOLINE, AND 4-RICHINOLAIDOYLMORPHOLINE.